In my personal experience, never compare with someone in front of your manager.
Instead say that you are not happy with current compensation especially given the current market situation or something like that.
And say the competition/same level companies are paying more for same background and experience.
The same way some junior is getting more than you a senior might be getting less than you.
Be as ambiguous as possible when you are saying you compared your salary with others.
After mentioning all of this, ask how can/will your manager help here.
There can be scenarios where a managers hand are really tied. But most managers just don’t like to pay.
(Record the response through your phone or somewhere to see how tactfully he is responding, no official use)
During the meeting, note down everything he is saying in your mail in front of him. And before you conclude send that as an MoM in the meeting room itself. Just say for your personal record only and nothing else.
Most important thing, never start with a complaint. Start off by asking feedback about your work. Use this to understand how he feels about your work. After he concludes (hopefully in a positive way) tell that you also have a concern. And then start this. Never, I repeat, never start the discussion, always follow up.